Wound dressings have significantly contributed to increased survivability from physical trauma by helping to control bleeding and protect the wound from entry of bacteria or other infective agents. Typically, wound dressing are generally flexible materials, such as gauzes, bandages, fabrics, etc., that can be used to treat wounds. In combat situations, wounds are often life-threatening and the time pressures associated with treating wounds may be amplified by ongoing hostilities. Especially prevalent on the combat battlefield are penetrating wounds that can be caused by gunshots or shrapnel.
Previous attempts to provide a quick and easily deployable device to treat wounds have included gauzes with an adhesive side that can be applied directly over wounds. Unfortunately, the pressure of the blood and fluids exuding from the wounds has allowed the fluids to seep in-between the skin and adhesive, thereby eventually separating the adhesive from the skin.
Also, in some situations, a condition known as a pneumothorax, also known colloquially as a “collapsed lung,” can occur with a penetrating wound. The outer portion of the lung is composed of two tissue layers: the internal visceral pleura that cover the lungs, and the external parietal pleura that is attached to the chest wall. The space between the visceral and parietal pleura is known as the pleural space. Under normal conditions, the visceral and parietal pleura are nearly flush against one another with the pleural space usually containing only a thin layer of pleural fluid. However, when an aperture to the pleural space is created by a penetrating chest wound, air or fluids can enter the pleural space and the resulting air or fluid pocket can compress the inner portion of the lung, making breathing extremely difficult.
Pneumothoracies are generally classified into two types: tension and non-tension. The latter can occur with trauma, various illnesses, or even spontaneously. While non-tension pneumothorax can lead to chest pain and difficulty breathing because the lung is incapable of expanding fully, it is generally of lesser concern than tension pneumothorax, which is a medical emergency. A tension pneumothorax occurs when a penetrating chest wound effectively forms a one-way valve into the chest cavity that allows airflow into the pleural space while preventing airflow out. In a tension pneumothorax, each inhalation traps air in the chest, increasing pressure on the lungs and ultimately causing them to collapse. In some cases, one lung can be pushed into the heart and the other lung, interfering with the functions of these organs. As the blood vessels of the lung are compressed, the vascular pressure increases and puts pressure on the right ventricle of the heart, possibly leading to cardiac failure.
Some wound dressings were designed to prevent the intake of air and/or fluid into the chest cavity for penetrating chest wounds. However, these dressings are inadequate for battlefield environments, where extreme rigors and demands are placed on medical equipment and personnel. Common failures of these devices during combat conditions can range from inadequate adhesive for attaching to the skin, insufficient size for covering large wounds, complexity of use, and length of time needed to deploy the bandage.